Abstract: An experiment was carried out to evaluate the effect of intramuscular injection of different concentrations of sulfated glucomannan on protection and immune function of broilers artificially infected with infectious bursal disease virus. 270 1-day-old AA broilers were randomly divided into five treatments ,Ⅰ,Ⅱ,Ⅲ,Ⅳ group with 55 birds,Ⅴ group with 50 birds. At 18-day-old three groups were injected with 1, 2 and 4 mg/mL concentrations of sulfated glucomannan and each 1 mL for 3 days, the other two groups as a virus control and conventional control. At 21-day-old except normal control the other four groups were infected with the same dose of bursal disease virus, a trial period for 3 weeks. The results showed that injection of high concentrations of sulfated glucomannan can reduce morbidity and mortality of chickens significantly; in 1 week post-infection high concentrations group compared with the control group was able to significantly promote lymphocyte proliferation (P＜0.05); in the two weeks post-infection, antibodies of high concentrations group was significantly higher than the virus control group (P＜0.05). The rest period of each group compared with the viral group was able to raise antibody levels but the difference was not significant (P＞0.05).

Key words: infectious bursal disease virus; sulfated glucomannan; lymphocyte; antibody